Page 937 of 1500
ENGINE COOLING DIAGNOSIS
ENGINE COOLING14-22
STEP 4. Check the fan controller connector A-24,
intermediate connector A-13 and engine-ECU connector
B-21.
Q: Are these connectors in good condition?
YES : Go to Step 5.
NO : Repair or replace the connector. Then go to Step 8.
Page 938 of 1500
ENGINE COOLING DIAGNOSIS
ENGINE COOLING14-23
STEP 5. Check the harness wire between fan controller
connector A-24 terminal 2 and engine-ECU connector
B-21 terminal 71.
Q: Are these harness wires in good condition?
YES : Go to Step 6.
NO : Repair the damaged harness wire. Then go to Step 8.
Page 939 of 1500

ENGINE COOLING DIAGNOSIS
ENGINE COOLING14-24
STEP 6. Check the fan controller.
(1) Disconnect fan controller connector A-24.
(2) Back out connector terminal pin 2 from connector housing.
(3) Reconnect the connector with connector terminal pin 2 still
removed.
(4) Turn the ignition switch to the "ON" position.
(5) Check for the cooling fan operation.
The cooling fan rotates. (with connector terminal pin 2
disconnected)
(6) Check for the cooling fan operation.
Using a suitable probe connect the fan controller termi-
nal 2 at controller side to earth.The cooling fan stops.
(When pin 2 of fan controller is connected to earth)
(7) Turn the ignition switch to the "OFF" position.
(8) Disconnect fan controller connector A-24, and re-locate
connector terminal pin 2 into connector housing.
(9) Reconnect the connector with connector terminal pin 2
installed correctly.
Q: Does the cooling fan rotate? And when the fan
controller pin 2 is connected to the body earth, does
the cooling fan stop?
YES : Go to Step 7.
NO : Replace the fan motor and fan controller (Refer to
14-25). Then go to Step 8.
Page 940 of 1500

ENGINE COOLING DIAGNOSIS
ENGINE COOLING14-25
STEP 7. MUT-III self-diag code
Check if an MPI system self-diag code is set. (Refer to GROUP
13A - Trouble shooting 13A-5)
Q: Diagnosis code set?
YES : Inspection chart for diagnosis code (Refer to GROUP
13A - Trouble shooting 13A-5)
NO : Replace the engine-ECU (Refer to GROUP 13A,
Engine-ECU 13A-675 ) Then go to Step 8 .
STEP 8. Check the symptoms.
Q: Does the radiator fan motor and the condenser fan
motor operate correctly?
YES : This symptom is complete.
NO : Return to Step 1.
INSPECTION PROCEDURE 5: Radiator Fan does not Operate
.
Radiator Fan and Condenser Fan Drive
Circuit
.
TECHNICAL DESCRIPTION
The cause could be a malfunction of the radiator fan
motor or an open circuit between the fan controller
and the radiator fan motor.
.
TROUBLESHOOTING HINTS
Malfunction of radiator fan motor
Malfunction of fan controller
Refer to component locations GROUP-1
Refer to configuration diagrams GROUP-1
Refer to circuit diagrams GROUP-1
DIAGNOSIS
Replace the radiator fan motor and fan controller assembly.
Q: Does the radiator fan operate correctly?
YES : There is no action to be taken?
NO : Repair the wiring harness between the fan controller
and the radiator fan motor.
INSPECTION PROCEDURE 6: Condenser Fan does not Operate
.
Radiator Fan and Condenser Fan Drive
Circuit
.
TECHNICAL DESCRIPTION
The cause could be a malfunction of the condenser
fan motor or fan controller.
.
TROUBLESHOOTING HINTS
Malfunction of condenser fan motor
Malfunction of fan controller
Refer to component locations GROUP-1
Refer to configuration diagrams GROUP-1
Refer to circuit diagrams GROUP-1
Page 941 of 1500

ON-VEHICLE SERVICE
ENGINE COOLING14-26
DIAGNOSIS
STEP 1. Check the condenser fan motor.
Condenser fan motor check. (Refer to GROUP 55, Condenser
and Condenser Fan Motor.
Q: Is the condenser fan motor in good condition?
YES : Go to Step 2.
NO : Replace the condenser fan motor, then go to Step 3.
STEP 2. Check the fan controller.
Refer to 29.
Q: Is the fan controller in good condition?
YES : Go to Step 3.
NO : Replace the fan motor and fan controller (Refer to
14-25). Then go to Step 3.
STEP 3. Check the symptoms.
Q: Do the condenser fan operate?
YES : This symptom is complete.
NO : Return to Step 1.
ON-VEHICLE SERVICE
ENGINE COOLANT LEAK CHECKM1141001000333
When pressure testing the cooling system, slowly
release cooling system pressure to avoid getting
burned by hot coolant.
Be sure to completely clean away any moisture from
the places checked.
When the tester is taken out, be careful not to spill any
coolant.
Be careful when installing and removing the tester and
when testing not to deform the filler neck of the radia-
tor.
1. Check that the coolant level is up to the filler neck. Install a
radiator tester and apply 160 kPa (23 psi) pressure, and
then check for leakage from the radiator hose or
connections.
2. If there is leakage, repair or replace the appropriate part.
Page 942 of 1500
ON-VEHICLE SERVICE
ENGINE COOLING14-27
RADIATOR CAP PRESSURE CHECKM1141001300419
NOTE: Be sure that the cap is clean before testing. Rust or
other foreign material on the cap seal will cause an improper
reading.
1. Use a cap adapter to attach the cap to the tester.
2. Increase the pressure until the indicator of the gauge stops
moving.
Minimum limit: 83 kPa (12 psi)
Standard value: 93
123 kPa (14 18 psi)
3. Replace the radiator cap if the reading does not remain at or
above the limit.
ENGINE COOLANT REPLACEMENTM1141001200478
When removing the radiator cap, use care to avoid
contact with hot coolant or steam. Place a shop towel
over the cap and turn the cap counterclockwise a lit-
tle to let the pressure escape through the vinyl tube.
After relieving the steam pressure, remove the cap by
slowly turning it counterclockwise.
1. Drain the water from the radiator, heater core and engine
after unplugging the radiator drain plug and removing the
radiator cap.
Page 943 of 1500
ON-VEHICLE SERVICE
ENGINE COOLING14-28
2. Drain the water in the water jacket by unplugging the drain
plug of the cylinder block.
3. Remove the radiator condenser tank assembly and drain the
coolant.
4. Drain the coolant then clean the path of the coolant by
injecting water into the radiator from the radiator cap area.
5. Apply the designated sealant to the screw area of the
cylinder block drain plug, and then tighten to the standard
torque.
Specified sealant: 3M
AAD Part No.8731 or equiva-
lent
Tightening torque:
39
5 Nm
6. Securely tighten the radiator drain plug.
7. Assemble the radiator condenser tank assembly.
Page 944 of 1500

ON-VEHICLE SERVICE
ENGINE COOLING14-29
Do not use alcohol or methanol anti-freeze or any
engine coolants mixed with alcohol or methanol
anti-freeze. The use of an improper anti-freeze can
cause corrosion of the aluminum components.
8. By referring to the section on coolant, select an appropriate
concentration for safe operating temperature within the
range of 30 to 60 %. Use special tool MB991871 to refill the
coolant. A convenient mixture is a 50 % water and 50 %
antifreeze solution [freezing point:
31C (32.8 F)].
Recommended antifreeze: Long Life Antifreeze
Coolant or an equivalent
Quantity:
8.7 Litres
NOTE: For how to use special tool MB991871, refer to its
manufacturer’s instructions.
9. Reinstall the radiator cap.
10.Start the engine and let it warm up until the thermostat
opens.
11.After repeatedly revving the engine up to 3,000 r/min several
times, stop the engine.
12.Remove the radiator cap after the engine has cooled, and
pour in coolant up to the brim. Reinstall the cap.
Do not overfill the radiator condenser tank assembly.
13.Add coolant to the radiator condenser tank assembly
between the "FULL" and "LOW" mark if necessary.
ENGINE COOLANT CONCENTRATION TESTM1141001100396
Refer to GROUP 00, RECOMMENDED LUBRICANTS AND
LUBRICANT CAPACITIES TABLE 35.
FAN CONTROLLER CHECKM1141007400113
1. Remove the fan controller connector.
2. Turn the ignition switch to the "ON" position, and measure
the voltage between the harness-side connector terminals.
Standard value: System voltage